Messages in this thread | | | Date | Wed, 22 Oct 2008 20:25:30 +0300 | From | Török Edwin <> | Subject | Re: [PATCH 4/4] Implement semaphore latency tracer |
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On 2008-10-22 20:22, Peter Zijlstra wrote: > On Wed, 2008-10-22 at 17:48 +0200, Ingo Molnar wrote: > >> * Török Edwin <edwintorok@gmail.com> wrote: >> >> >>> On 2008-10-22 18:28, Ingo Molnar wrote: >>> >>>> hm, but the most common synchronization primitive are mutexes - and >>>> those are not covered by your patchset. >>>> >>>> >>> Indeed. I've seen a patch from Jason Baron to introduce tracepoints >>> for mutexes, but the conclusion was that the tracepoints should be in >>> lockstat instead. >>> >>> And if lockstat is enabled Peter Zijlstra's 'contend with points' >>> patch seems to do exactly what I want to. >>> >>> However I think it would be useful to have (a tracepoints based?) >>> latency tracker, which can be enabled/disabled at runtime, and which >>> doesn't add any data to the mutex/semaphore structures. My patchset >>> was a first attempt towards that, but it seems that such use of >>> tracepoints is not welcome at this time? >>> >>> Please tell me if I should continue working on this, or if I my >>> patches are designed totally on the wrong way. >>> >> i think if you hook into Peter's lockstat APIs that should give us a >> pretty good tracer, with no ugliness introduced. That would be rather >> interesting. Peter, do you concur? >> > > Yes, I've already suggested this. Use the exact same hooks that > lockdep/lockstat use.
Ok, I'll work on this when I get some time :) [hopefully this weekend test the 'contend with points patch', next weekend write the new tracepoints]
Best regards, --Edwin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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